两种结构性软土的工程特性分析

Research on Two Kinds of Structured Soft Clay Engineering Characteristics

选取黄石与青岛地区软土为研究对象,进行高压固结、固结不排水剪切等结构性试验。分析土结构性对固结特性、固结系数、应力-应变特性、强度包线、孔隙水压力特性的影响,利用微观结构变化对其进行了解释。结果表明,土的结构性越强,随着压力的增加,原状土的Cv降低的幅度也越大。围压小于σk时,应力-应变曲线上出现应力平台;围压高于σk时,曲线上没有明显的应力平台。结构极疏松、孔隙比大的软土,剪切过程中可能出现剪缩的情况。U-q曲线表现出平缓—陡升—平缓的阶段性。

The structural characteristics of soft clay is an important factor affecting engineering properties.Based on a series of structural tests on soft clay in Huangshi and Qingdao areas,such as consolidation tests and CU tests.Analyzing impacting of the structural characteristics on consolidation properties,consolidation coefficient,stress-strain behaviors,strength envelope and pore water pressure influence.The results show soil structure characteristics was stronger,along with pressure increase,the scope which undisturbed samples consolidation coefficient reduces was bigger.The stress-strain curve presented stress platform which the pressure was smaller than σk,and curve had not obvious stress platform after the pressure is higher than σk.The structure was extremely loose,the void ratio big soft clay possibly appeared shear shrinkage in the shearing process.The U-q curve displayed gently—rises—the gentle gradualness steep.